Abstract
A histological comparison has been made of the giant cells in 10 cases which had been diagnosed as central giant cell granuloma of the jaws and 10 cases diagnosed as giant cell tumor of long bone. The numbers of nuclei in each of 50 giant cells were counted in the 20 lesions. The giant cells were measured in order to compare their sizes in the respective lesions. It was found that the giant cells of the jaw lesions contained significantly fewer nuclei than those of the lesions in other bones. Secondly it was found that cells in the lesions of long bone have significantly larger dimensions than those in the jaw lesions. There was, however, an area of overlap. It was concluded that these data supported the view that giant cell tumor and giant cell granuloma are distinct entities. Some giant cell lesions of long bones are, however, morphologically indistinguishable from giant cell lesions of the jaws; and conversely giant cell lesions of the jaws are indistinguishable from some giant cell lesions of the long bones. It seems possible, therefore, that some jaw lesions are giant cell tumors and that some giant cell lesions outside the jaws are giant cell granulomas.